In order to observe a fine region of an object, a scanning electron microscope (SEM), a transmission electron microscope (TEM), or the like, is used. In general, in these devices, a housing, in which a specimen is disposed, is subjected to vacuuming, an atmosphere of the specimen is in a vacuum state, and then the specimen is imaged. However, a biological or chemical specimen, a liquid specimen, or the like, is damaged, or a state thereof is changed, due to the vacuuming. On the other hand, there have been increased needs for observing such specimens by using an electron microscope and, recently, there has been a growing demand for an SEM device, in which an observation target specimen can be observed at atmospheric pressure, at desired gas pressure, or in a desired gas species.
Therefore, in recent years, a known literature discloses an SEM device in which a specimen can be disposed at atmospheric pressure, at a desired gas pressure, or in a desired gas species, by providing, between an electron optical system and the specimen, a barrier film or a fine hole that can transmit an electron beam, and thus, separating a vacuum state, in which the electron beam travels, from an atmosphere of a specimen. The known literature discloses the device in which an SEM observation can be performed at atmospheric pressure and a specimen position can be changed in a state in which the barrier film is not in contact with the specimen by using a specimen stage disposed immediately below the barrier film.